Means for packing insulation material



April 13', 1948. I R, VPAULEY I 2,439,605

MEANS FOR PACKING INSULATION MATERIAL Filed April 20, 1942 Patented Apr. 13, 1948 MEANS FOR PACKING INSULATION MATERIAL Robert D. Paulcy, Cloquet, Minn assig nor to Wood Conversion Gompany,. Cloquet, Minn, a

corporation of Delaware Application April 20, 1942, Serial No. 439,678

The present invention relates to the packing of insulation materials, such as fibers, by differential pneumatic pressures.

In the co-pending application of Heritage Serial No. 477,753, filed March 2', 1943, as a continuation-in-p'art of a generic application Serial No. 294,212, filed September 9, 1939, there is disclosed a process and devices for blowing fibers, flakes, members and other insulation-forming material which packs or entangles to form a self-sustaining structure, into aspace to build up an insulating body. In said description reference is made to a space to be filled with suchinsulation, which space is exemplified by a box-like structure with bottom and sides. The said space is such as that defined by a domestic refrigerator cabinet lying on its back with the door-opening directed upwardly, and by a fixture fitted into the cabinet as a dummy food compartment. The fixture is a special form provided variously with screen openings to permit exhaust of air used as a vehicle to bring in the insulation material. In actual practice, the said space is filled to provide an integrated continuous thermal insulation packing by use of the said fixture. Then the fixture is withdrawn, leaving the said packing unsup-. ported on the faces where the fixture theretoiore defined the space. The true food "compartment is then inserted where the fixture had been. This results in the packing being continuous in all the space between the walls of the cabinet and the Walls of the food compartment.

such practice, especially using feltahle fiber, diiiioulties are experienced on the s ide faceshaving :a large vertical "area so packed against a fixture wall which is imperforate over suhstam tially the interior part of said area. There is a tendency, frequently exerted, for such vertical portionof the structure, comparableito a box side wall, to bulge inwardly and occasionally fall into the opening to be fill-ed by the food compartment. The poorer the felting qualities of the material used, the greater is the tendency to collapse.

It is the object or the present invention to provide for pneumatically packing 'fel't'able insulation material to form a relatively thin and high vertical body covering a large vertical area, which body is stable when unsupported on one face by reason of removal or a wall defining said space originally.

In other words, in the specific case described;

it is an object of the invention to prevent side:

wall bulging or collapse.

It is aspecific object of the invention to provide a fixture presentingv in use a vertical side wall 3 Claims. (Cl. 20101).

of large area, which wal1 is largely impertorate, and which. has imperforate horizontally spaced panels separated by vertically elongated and relatively narrow screen areas.

Various other and ancillary obj ects and advantages of the invention will be apparent from the fol-lowing description and explanation of the invention as it is set forth and explained by reference to the accompanying drawings, :in which the invention explained by reference to structures employed with wood fibers having excellent felting properties compared to flakes, or to mixtures, or other insulating material in particle form. l

In the drawings:

Fig; I is" a view representing the appearance of a' filled cabinet made with the fixture of Fig. 3.

Fig. 2 is across section taken on line 5-5 of Fig. 1. t

Fig. 3 is a view of a fixture embodying the present invention, with one side wall rectified to the plane of the bottom wall only for the purpose of illustration.

Fig. 1 represents the' goalto be attained. Numerallll' represents a portion of a cabinet of a refrigerator lying. on its back; providing av boxlike shell. -Some cabinets have the. illustrated flange ll aboutthe opening, and some do not. However, the difficulties to be remedied are met within both types. Numeral l2- represents fiber packed into the cabinet shell in box-like form to provide: an opening in size to receive the food compartment.

The reinforcing ribs indicated 31' in Fig. 1 are effected by the present invention. Consider that these are lacking andvthexstructure at them is like the indicated surrounding structure of the felted fiber. So oonsideredthe filled cabinet is a product which when "freshly made has exhibited defects. The central portion or the long sidewalls, (corresponding to the vertical sides of the upright refrigerator) may bulge': or collapse, and the bottom also may bulge upwardly in the position shown in l,;wh'en formed" as hereinafter described by'the older methods.

Fig. 3 represents roughly the type of fixture which has been employed to produce those structures of the defective type described, which tend to or do collapse or bulge, It is a box-likefixture, or dummy food compartment, of dimensions to define the interior walls of the space to be filled with insulation I 2. (Fig. 1). It has a base or floor section 40 and four side panels 4|, 42', 43 and 44, the latter being shown for convenience in illusnation as rectified to the plane or the floor 40..

by having the various screen areas 46 near the tops of the panels and at the corners in the said panels and base, to release the air, filter the fiber, and induce a felted formation. The principles of the method are explained in detail in said prior application.

As a result of the use of the aforesaid fixture of Fig. 3, without the indicated screen areas 44, large areas of the felt lack a structure and strength which will maintain themselves in a vertical position unsupported from the inside, where the vertical area'is large and horizontally long in proportion to the thickness of the felted panel. 1

Assume a fixture of Fig. 3 minus the screen areas 41 to be in the shell ill of Fig. 1, and the material blown in to fill-the intervening space. Thus, the material will pack from the top-most filter areas 46 downwardly, around the corners at the bottom, and then toward the inlet conduit 48. This results in a horizontally laminated formation, produced under pressure. As a result, substantially all the elasticity of the formation is exerted vertically in the side walls, and horizontally at the bottom (back of cabinet). Upon removal of the fixture and its restraint, the elasticity causes bulges 'in the long sides and bottom. The bulge at the bottom causes little difficulty, because upon inserting the food compartment it goes back into place under desirable compression. However, at the side walls, there is frequent collapse.

With fibers, the tendency to expand by the elasticity is transient, and upon standing the elastic force is converted into felting energy by rearrangement of the fibers. Thus, a cabinet so filled with the so-modified fixture of Fig. 3 may be allowed to stand for a considerable period of time before removing the fixture, to minimize or avoid the tendency to bulge. -However, in commercial operations of this sort, it is not practicable to allow for such a' time interval. The fixture must be removed immediately to permit filling another cabinet.

The present invention aims to alter the formation of the felt structure to provide selected portions of the felt with a different structure having greater strength and different elastic forces than the rest, whereby the selected portions act as a reinforcement, ,or as a break in the forces producing bulging. This is illustrated in Fig. 1. wherein the integrated felt form 30 in cabinet I9, has one or more vertical ribs 3! of a stronger and a differently felted-structure than the adjacent portions. The difference is illustrated in Fig. 2, by the more heavily shaded portion 3| which is formed over a limited screen area 32 in a fixture wall having the horizontally spaced imperforate' panel portions 33 and 34 separated by the narrow vertically elongated screen area 32. v

I Where the felt is formed by exhaust of the air-vehicle outwardly from thefelt 30-3l (Fig. 2) through the, screen area. 32,. any finer fibers tend to filter out in the region 3 l giving it great r density and strength to provide the desired reinforcement or strut-formation. But also the formation tends to grow laterally from the areas 3| (Fig. 1) as well as downwardly, whereby a less laminated and a more random formation begins at areas 3| and extends therefrom into the surrounding area. The areas other-than Si in Fig. 1," which lie over screens are indicated, only by stippling.

The design of the fixture varies with the particular design of-the box to be packed. For the structure shown in Fig. 1 a suitable fixture is shown in Fig. 3. In Fig. 6 the box-like form or fixture has an outside area substantially duplicating the exterior areas of thefood compartment for the box If]. The screen areas 41 include those introduced in the long'side walls to overcome the undesired defects. These are termed vertical intermediate screen areas, in that they extend generally vertically, compared to those horizontal areas 46, and lie intermediate the ends of the containing panel. 1

The conduit 48 in the center of the floor 4 is connected to a pneumatic supply of suspended fiber. It has an end opening 49 coincident with a like opening in the bottom or floor 40. suitable arrangement for creating a differential pressure, a movement of air and insulating par: ticles is effected through conduit 49 into. the space to be filled. Thus, when the fixture is in the .box IE] and the conduit 48 is connected to an outlet of a fan, into the inlet of Which,'or into the outlet pipe of' which, fiber is fed, a charge of dispersed fiber is carried first to the remote screens 46 shown at the top of the fixture of Fig. 3', Where it is felted and packed at a density determined in part by air pressure. As it packs, the edge surface of the felt being formed advances toward the pipe outlet 49,but the advancing surface changes shape in-accordance with the arrangement of the screen outlets. The vertical screen areas 41 are very soon covered, and the advancing surface may move in part horizontally as well as vertically, away from such areas. The result is that a different and more random formation of fiber occurs over and away from the screens "41.. These areas are those described as 3| in Figs. 1 and 2. They give support and relief to the resultin unitary mat, which prevent Vertical side-wall collapse and bulging.

The extent to which the areas i'l are supplied, the extent of the space between two of them, the extent of their length, and the extent of their area, are a subject not capable of being defined.

The differential air pressure, the depth of the I felt, the properties ofthe insulating particles, and the over-all design of the fixture are all factors which are effective to control the character of the formation. Experience has shown that results are best obtained by a liberal initial supply of screen areas 46 and 41 generally as indicated in a fixture such as that in Fig. 3. One or more of these areas may be in whole or in part blocked off by use of adhesive tape to adapt thefixture to particular conditions for produc-' ing desired degrees of uniformity in density over the entire area to be filled.

Although the invention has been specifically illustrated by reference to its embodiment in the fixture for and in the production of refrigerators, it is to be understood that the invention is not confined to this embodiment. Any vertically standing slab-like body'of fiber which is to be unsupported on one face fora time, where by it may be subjected to forces or reactions tending to cause its collapse, may be formed by use of a facial-member having imperforate panels horizontally spaced, and separated by one or more vertically elongated fiber-retaining gasventing areas.

Although the invention has been explained by reference to the structures actually employed with wood fibers, it is to be understood that the principles of the invention apply equally well to cases where the feltable material which is used is not all wood fiber, or is some. other material or .mixture. It is to be observed that the endwalls of the fiber-box-structure described, corresponding to the top and bottom positions of the food compartment, are sufilciently short compared to the lengths of the other faces, that the support from the corners is suilicient to prevent side-wall collapse. It is to be understood that where the feltable material employed has such packing qualities that these short-length walls also tend to collapse, a vertical elongated screen area comparable to screen Al may be used in the corresponding walls of the fixture to correct the defect.

Such structures and uses of the invention are comprehended within the scope of the appended claims.

I claim:

1. A fixture for use in insulating refrigerator cabinets by a pneumatic process, comprising a box-like form in the shape of a dummy for afood compartment for said cabinet, said fixture having a box-like bottom and four side walls corresponding generally to the back and side walls of said food compartment, the total area of said fixture having perforate area and imperforate area, of which total area perforate area in the bottom provides inlet area for introducing moving gas containing suspended particles of insulating material, and of which total area at least one side wall has filtering area and filtering means covering said area in the form of a narrow elongated area extending in the direction from bottom to top of the fixture in ermediate the ends of the containing wall of the fixture, said elongated filtering area being flanked by imperforate area.

2. A fixture for use in insulating refrigerator cabinets by a pneumatic process, comprising a box-like form in the shape of a dummy for a food compartment for said cabinet, said fixture having a box-like bottom of rectangular form and two relatively long side walls and two relatively short side walls corresponding generally to the back and side walls of said food compartment,

6 .l x the total area of said fixture having perforate area and imperforate area, of which total area perforate area in the bottom provides inlet area for introducing moving gas containing suspended particles of insulating material, and of which total area the said two relatively long side walls each have filtering area and filtering means covering said area in the form of a narrow elongated area extending in the direction from bottom to top of the fixture intermediate the ends of the containing wall of the fixture, said elongated filtering area being fianked by imperforate area.

3. Apparatus for forming a thin upright body of felted fiber in a space between two opposed vertical walls for use as thermal insulation, which body resists collapse when one of said walls is removed, which comprises, means providing an imperforate horizontally elongated vertical wall, means providing a horizontally elongated vertical fiber-confining second wall opposed to and spaced from said imperforate wall, said second wall containing in an area intermediate its horizontal extremities and closer to the middle between said extremities than to said extremities one or more narrow elongated vertically extending filtering- 7 means capable of retaining the said fiber and of passing gas, said second wall being substantially imperforate on both sides laterally of said filtering means, and other fiber-confining means to partition said space from the atmosphere except for one or more openings through which. to introduce into said space moving gas having feltable fiber in suspension, whereby when said gaseous suspension is introduced into said confined space in quantity to pack said space with felted fiber, gas is released in part at least through said narrow elongated vertically extending filtering means to build up immediately in contact with said filtering means a difierent fiber-felt formation than is built up laterally adjacent thereto, which firstmentioned formation provides reinforcement of the resulting fiber-felt against collapse upon removal of said second wall containing said filtering means.

ROBERT D. PAULEY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,827,858 Tannery Oct. 20, 1931 1,923,195 Finck Aug. 22, 1933 2,054,323 Holbrook Sept. 15, 1936 Certificate of Correction Patent No. 2,43%);605. April 13, 1948.

ROBERT D. PAULEY It is hereby certified that errors appear in the printed specification of the above numbered patent requiring correction as follows: Column 2, line 44, before the nu merel1insert Fig.; column 3, line 8, before the word pipe insert of; line 18, for the reference numeral 44 read 4? column 4, line 13, for Fig. 6 read Fig. 3; and that the said Letters Patent should be read with these corrections therein that the same may conform to the record of the casein the Patent Ofiice.

Signed and sealed this 11th day of May, A. D. 1948.

THOMAS F. MURPHY,

Assistant Uommz'ssianer o f Patents. 

